I have a 1999 3.4 6 cyl toyota tacoma and it says i have a misfire on cylinders 2 and 6 i changed the ignition coil and didnt help any. I have no power when i take of and it runs about 3500 rpms going 75 mph, it shakes bad when i deaclerate what could be the problem?

 

Your probably better to start your own thread then resurrecting an 11 year old thread, unless you took your truck to the same guy li_runner did or performed the same tune up.

Your RPM's at 75mph shouldn't change ever it will always be 3500RPM in that gear at that speed. Start with plugs & wires & boots inspection/replacement paying close attention to #2 & #6 and do a compression test and let us know if anything comes up in a new thread. #5 Coil supplies power to #2 cyl, & #3 Coil Supplies power to #6, be sure to check all the connections between them and insure the wires are connected to the correct plug, you may have mixed up #2 & #6 wires.

 

OP, created a new thread for you.

Welcome to YT.

 

Remember it can be any where in the circuit from the ECM any of the wires the spark plugs

You changed the coil ??

What do those plugs look like ??

Reading the plugs can tell you more of what is going on with those two cylinders .

 

x2 on checking the plugs. Tell more about what's been replaced, how long ago, CEL codes if any, that sort of thing. Switch out the coil on the misfiring cylinder with one from a good cylinder and see if that affects the misfire to rule out a bad coil. Good luck!